The present invention relates to an apparatus and method for aligning a multiplicity of chip parts in a row and delivering the chip parts in sequence.
Known part-aligning apparatus of the above-mentioned kind include bulk feeders and vibrating ball feeders. Bulk feeders are roughly classified into pneumatically driven bridge-breaking type feeders and bridge-breaking type feeders which use an upward-thrusting pin in operation. In the case of the pneumatically driven type of feeder, it is difficult to adjust the amount and direction of airflow. In the case of the upward-thrusting pin type of feeder, whenever an operation is performed, the pin impacts the parts and so the parts tend to be easily scratched or damaged. In both types, every chip part is forced toward a funnel-like exit. Therefore, if a bridge-breaking operation is performed once, the bridge may be immediately restored. As a consequence, the efficiency at which parts are aligned is low. In the case of the vibrating ball type of feeder, bridges are not readily formed. However, this equipment is expensive. Also, unwanted vibration is easily transmitted to other apparatus. Furthermore, a large space is required for this type of equipment.
A part-aligning apparatus free of these problems is proposed in Japanese Unexamined Patent Publication No. 143164/1996. This apparatus comprises a cylindrical stocker for holding chip parts, an annular body disposed on the outer surface of the outer curved wall of the stocker, and a rotary disk having an annular indexing portion. This indexing portion is rotatably disposed in the gap between the outer curved wall of the stocker and the inner surface of the annular body. The indexing portion has a plurality of chip-holding recesses for individually seizing the chip parts. A chip discharge hole in communication with a chip storage portion is formed near the bottom of the outer wall of the stocker and in the path over which the chip-holding recesses are moved. In this case, movement is provided only by rotary motion, and accordingly, it is easier to make an adjustment. The chip parts are damaged less. In addition, the apparatus can be easily built to have a smaller size.
The above-described part-aligning apparatus requires at least the stocker, the annular body, and the rotary disk. Therefore, this apparatus is complex in structure and often breaks down. It is necessary that the rotary disk has chip-holding recesses arranged circumferentially, the recesses conforming to the shapes of the individual chip parts. In order to align micrometer chip parts having a length of about 1 mm long, the chip-holding recesses must be processed in correspondingly small size. Hence, the apparatus is very complex in structure and laborious to machine, thus increasing the cost.
The chip parts are held in series (e.g., the chips are held adjacent to each other in a line) by the chip-holding recesses in the indexing portion of the rotary disk. As the disk turns, the chip parts are forced toward a chute. Therefore, if the chute becomes clogged or overflows for some reason, a chip part subsequently fed in will be caught in the chute. As a result, the chip part may be damaged or the apparatus itself may break down. At this time, therefore, it is necessary to quickly stop the rotary disk using a "full occupation" sensor.